Auxiliary heater.



L. NJGILMAN. AUXILIARY HEATER.

APPLICATION FILED MAR. 4, 1912.

Patented Nov. 24, 1914.

Fulfil LEWIS N. GILMAN, OF ALLERTON, MASSACHUSETTS;

AUXILIARY HEATER.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed March 4, 1912. Serial No. 681,446.

To all whom it may concern:

Be it known that I, LEWIS N. GILMAN, a citizen of the United States, and resident of Allerton, in the county of Plymouth and State of Massachusetts, have invented an Improvement in Auxiliary Heaters, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention is an auxiliary heater for conserving the heat contained in the smokepipe which would otherwise be lost up the chimney, and using said heat for heating the otherwise cold air in a cold-air box or a water coil, and delivering it where desired for househeating purposes.

In the preferred form of myinvention, I provide means for diverting the products of combustion and compelling them and the cold air or water to travel with a retarded movement in a circuitous path in such relation that the heat from said products of combustion is necessarily-absorbed or extracted by the cold air or water.

A further object of my invention is to compel all the heat which is transmitted from said diverted products of combustion,

to be delivered to the said cold air in the cold-air box or to the water coil, as distinguished from being delivered or radiated into the surrounding room through which the smoke-pipe passes.

Other objects of the invention are to check and steady the draft from a stove or furnace and insure a more even combustion therein, and to provide a smoke-pipe heating device which can be readily attached to any existing pipe and which will be economical to manufacture.

An important feature of my invention is that the cold air flows in actual contact with the direct smoke pipe as well as with the indirect smoke pipe, and therefore is constantly absorbing heat, whether the draft is in one pipe or the other, and it is not necessary to turn the draft into the convolutions of the indirect pipe in order toimpart heat to the cold air.

In the preferred embodiment of my invention herein illustrated, it is to-be understood that the water coil, although shown in combination with the air drum and a smoke pipe, may be advantageously utilized without the air drum and in combination alone with a smoke-pipe.

.apart and leave a substantial area of the direct pipe exposed, as illustrated in the drawings. Butterfly dampers 5 and 6 of usual type are arranged in the pipes 1 and 2 so that the draft may be diverted from the pipe 1 into the indirect pipe 2. A damper 7 may also be provided in the upper end of the pipe near the chimney. Surroun ding the pipes 1 and 2 is a drum 8 having an inlet pipe 9 and a damper 10 arranged therein. The drum 8 is preferably in con tact substantially throughout the entire length of the convolutions of the indirect pipe 2, so that air admitted through the inlet 9 will be forced to follow the spiral course of the pipe 2, also flowing around the direct pipe, as will be readily understood on reference to Fig. 1. The upper end of the drum 8 is formed into a heating chamber 11, from which one or more pipes 12 may lead into other rooms or apartments. In order to clean out the indirect smokepipe 2, a pluralityof openings 13 are arranged, as indicated, normally closed by shutters. smoke, etc., when diverted into the indirect pipe 2, flows through a considerably longer passage than through the pipe 1, and is somewhat retarded thereby and caused to flow evenly and steadily, creating a continuous and uniform draft on the furnace. The cold air coming through the inlet pipe 9 is thus forced into a correspondingly spiral flow and is enabled to absorb practically all the heat which would normally pass through the smoke-pipe up the ChlII 1- ney. But itwill be noted that the cold air is actually brought in contact with both the direct and the indirect pipes, and therefore is constantly absorbing heat irrespective of how the draft is turned through saidpipes.

Referring to Fig. 2, I have shown a water coil 14: arranged in the smoke-pipe 1 and It will thus be seen that the 4 also a coil 15 in the indirect pipe 2.. A suit able inlet pipe 16 and outlet 17 are arranged at any suitable points throughout the length of the smoke-pipe, these pipes connecting with a radiator or radiators and constituting a part of any Well known hot-Water heating system. The Water in the coil 14 Will absorb the heat passing directly through the smoke-pipe l, and this arrangement may be satisfactory in some instances, but prefer to use the Water coil 15 in the indirect smoke-pipe 2, either with or Without the air drum 8.

It Willbe seen. that l have provided a smokepipe heating device Which is economical to construct, simple to apply to any ea:- isting smoke-pipe, ellicient in service, and which will absorb and extract practically all of the Waste heat normally passing through a smoke-pipe, and prevent the radiation of such heat into the room orapartment through which the pipe passes, and will coney such heat to a different room or apartment. 1 have found that by means of the indirect srnoke-pipe 2, the draft through a furnace fire is greatly steadied and equalized and the combustion of fuel is rendered uniform, Whereas the draft through a direct smoke-pipe is subject to constant Variations, such as are caused by varying conditions of Wind and Weather, and which sometimes resuit in an excessive burning up of fuel. However, one of the most important advantages of my invention is that the cold air is con stantly being heated by the direct smoke pipe as Well as by the indirect smoke pipe when the draft is turned through the latter, and thus even when a fire is being first kindled and started, the cold air will at once begin to absorb heat from the direct smoke pipe hefore the draft is turned into the indirect pipe,

Having described my invention, What lt claim as new and desire to secure by Let ters Patent is:

A smoke-pipe heater, comprising an outer drum inclosing a direct pipe, an indirect pipe arranged around said direct pipe in spaced convolutions and in contact With the outer surface of the direct pipe and the inner surface of the drum, forming a helical air passage between said spaced convolutions, and means to turn the draft into either the direct or indirect pipes.

in testimony whereof, l have signed my name to this specification, in the presence of two subscribing Witnesses.

LEWIS N. GILMAN Witnesses JAMES R. Hononn, EDWARD MAXWELL, 

